A 10-month cyberespionage investigation has found that 1,295 computers belonging to international institutions in 103 countries have been spied on, and some circumstantial evidence suggests that China may be to blame.

The 53-page report, released on Sunday, provides some of the most compelling evidence of the efforts of politically motivated hackers. It also raising questions about their ties with government-sanctioned cyberspying operations.

The report describes a network that researchers have called GhostNet, which primarily uses a malicious software program called gh0st RAT (Remote Access Tool) to steal sensitive documents, control webcams and completely control infected computers.

"GhostNet represents a network of compromised computers resident in high-value political, economic and media locations spread across numerous countries worldwide," said the report, written by analysts with the Information Warfare Monitor, a research project of think tank The SecDev Group, and the Munk Centre for International Studies at the University of Toronto. "At the time of writing, these organizations are almost certainly oblivious to the compromised situation in which they find themselves."

The analysts did say, however, that they have no confirmation if the information obtained has been valuable to the hackers or whether it has been commercially sold or passed on as intelligence.

Although evidence shows that servers in China were collecting some of the sensitive data, the analysts were cautious about linking the spying to the Chinese government. Rather, China has a fifth of the world's Internet users, which may include hackers who have goals aligning with official Chinese political positions.

"Attributing all Chinese malware to deliberate or targeted intelligence gathering operations by the Chinese state is wrong and misleading," the report said.

However, China has made a concerted effort since the 1990s to use cyberspace for military advantage. "The Chinese focus on cybercapabilities as part of its strategy of national asymmetric warfare involves deliberately developing capabilities that circumvent U.S. superiority in command-and-control warfare," it said.

The analysts' research started after they were granted access to computers belonging to Tibet's government in exile, Tibetan nongovernmental organizations (NGO) and the private office of the Dalai Lama, which were concerned about the leak of confidential information, according to the report.

They found computers infected with malicious software that allowed remote hackers to steal information. The computers became infected after users opened malicious attachments or clicked on links leading to harmful Web sites.

The Web sites or malicious attachments would then try to exploit software vulnerabilities in order to take control of the machines. In one example, a malicious e-mail was sent to a Tibet-affiliated organization with a return address of "campaign@freetibet.org" with an infected Microsoft Word attachment.

As the analysts probed the network, they found that the servers collecting the data were not secured. They gained access to control panels used to monitor the hacked computers on four servers.

Those control panels revealed lists of infected computers, which went far beyond the Tibet government and NGOs. Three of the four control servers were located in China, including Hainan, Guangdong and Sichuan. One was in the U.S., the report said. Five of the six command servers were in China, with the remaining one in Hong Kong.

The report classified close to 30% of the infected computers as being "high-value" targets. Those machines belong to the ministries of foreign affairs of Bangladesh, Barbados, Bhutan, Brunei, Indonesia, Iran, Latvia and the Philippines. Also infected were computers belonging to the embassies of Cyprus, Germany, India, Indonesia, Malta, Pakistan, Portugal, Romania, South Korea, Taiwan and Thailand.

International groups infected included the secretariat of ASEAN (Association of Southeast Asian Nations), SAARC (South Asian Association for Regional Cooperation) and the Asian Development Bank; some news organizations such as the U.K. affiliate of the Associated Press; and an unclassified NATO computer.

GhostNet's existence highlights a need for urgent attention to information security, the analysts wrote. "We can safely hypothesize that it [GhostNet] is neither the first nor the only one of its kind," they said.